The Department of Justice has requested more information and details of the proposed arrangement between Microsoft and Yahoo. The scrutiny could spell disaster for Yahoo if the DOJ ultimately rejects the partnership.

Things are as tight as a tick over at Yahoo and Microsoft about the deal the pair have been discussing over the last months–as execs shuttle back and forth and forth and back and its boards deliberate on what will surely be one of the most important decisions for either company for the near-term future …

SAN FRANCISCO, USA: Less than a week after saying that Yahoo would be “cleaner and simpler without a Microsoft connection,” CEO Carol Bartz said on Monday that the struggling Internet giant can “take on” rivals Microsoft Corp and Google Inc. However, she dismissed the idea of striking a partnership with Time Warner Inc.’s AOL unit, Dow Jones reported on Monday.

Yahoo Inc.’s chief executive said Wednesday that she is open to joining forces with Microsoft Corp. so both companies can better compete in Internet search, but a deal would need a specific set of terms ? including “boatloads of money.”